Heating system



June 24, 1941. G. AMES HAL HEATING SYSTEM Filed llarh 51, 1939 3 Sheets-Sheet 1 'l' lll x M ;u H mi m WZ |V ,0f M@ ||HHH |1\1 m w June 24, 1941. J. G. AMI-:s s -rAL HEATING SYSTEM Filed March 31, 1939 3 Sheets-Sheet 2 mJf W yf @Z M@ w J. e. AMES Erl-AL vHEATING SYSTEM Filed arch 31. 1939 June 24, 1941.

3 Sheets-Sheet 3 Patented June 24, 1941 I nume s'rs'rm Jamel G. Ames and Norman C. Penfold, Chicago, 1 lll., signora to Autogas Corporation, Chicago, Ill., a corporation of Illinois Application Mann si. 193s, sex-tal No. 265,113#

7Clalms.

This invention relates to heating systems and more particularly to the control of systems'buming fluid fuel.

Due of the objects of the invention is to proviole a heating system including a furnace which may be connected either to a heat extractor or to a stack or the like. According to one important feature of the invention the system is normally operated automatically with the heat extractor connected to the furnace and an interlocking ar rangement is provided between the stack connec tion and the furnace to prevent manual operation oi the turnace except when the stack connection is open.

another object of the invention is to provide e heating system lincluding a valve controlled stach connection and a fuel control operated by a com mon lrey member so that the iuel control cannot be opened manually unless the stack connection is onen.

Stili another object of the invention is to provide a heating system including a heat extractor in which iiue gas is always drawn through the heat extractor as long as fuel is supplied to the syste.

@ther objects. advantages and novel features oi the invention will be apparent from the following description of the accompanying drawings. in which: f

Fig. l is a diagrammatic view of a heating systern embodying the invention:

Zeig. 2 andV Fig. 3 are enlarged partial sections showing different positions of the parte;

litig. 4 is an enlarged partial side elevation with parts in section;

lliig. 5 is a view from the right of Fig. 4:

itig. 6 is a partial view of Fig. 4 showing a difterent position:

Figs. 'l and 8 are partial sections of the fuel control valve showing different positions; v

liig. il is a top view of the fuel control valve;

Figs. 10 and 11 are sections of a flow switch in different positions.

Figs. 12 and 13 are circuit diagrams illustrating different operating conditions; and

Fig. 14 is an alternative circuit diagram.

The system illustrated in Fig. 1 includes a furnace of the type usually employed for domestic heating and which may be a hot air, hot water or steam furnace. As shown. the furnace is provided with a burner I2 extending into the .lower portion thereof and supplied with gas through a pipe It. The gas passes through a standard reducing valve ii and a motor controlled valve il to be described more fully hereinafter.

l0 or through any ctherH- to trated in Fig. 6.

Flue gas from the lfurnace flows out through a draft diverter 2l into a ilue pipe 22 leading to a T fitting 24. connected to a heat extractor shown as an elongated pipe 2l which may extend through any space desired to be heatedl and which is connected to an electrically driven blower 2l discharging to atmosphere..l The connection :than at one side a pipe-t9 leading to the usual stack raedpassage to atmosphere. 4 Ae leest eeen in litige. t to t n Mi @t ie nrovided in the ntting tttoeiose the entrance to the stacit tion tt. the demper is plvoted 4on le a chart tt having testneu tneretean arm tt en@ closed in n suitable llueintt atene side ci'the iitting.v The housing is provided in its top with a slot-.tovreceive a irevl member tavhlch is adapt ed to slip over the roei it so that `the rod may be e0 swung to open or close the valve.` iiiigs. fi and illustrate the valve" le closed nonnen with the rod t8 and ltey ber it vertical and with a groove :4 2 in the `ireyf member engaging the housing 3| so as. to prevent removal oi the irey mem 5 ber. ln order to remove the itey member, it must be swung substantially-to the horizontal position .-.to open the valve t2 and may then be removed through en enlargedgportion M of the slot in housing il. This positionoi' the parts is illus- In theI path of gas, flowing vertically through the housing 24 to the heat extractor pipe It, there is provided a vane il carried by a pivotedv lever Il. The lever is' normally urgedcounterclockwise to the position of Fig. Sby a Spring 59 and will be-xnoved clockwiseto the position of Fig. 2 by the velocity of gasfstriking the vane Il.

The vane ll is arranged to operate an electric switch I! which is normally .open and is closed 40 by the leverv when flue gas is flowing through the heat extractor. A' similar switch 54 is arranged in the housing 38 to be closed by the rod ll when the valve-J2 is closed and to spring open when the valve isopened vas shown inFig. 6.

i 'I'he electrically controlled fuel supply valve il is shown as. a standard motor valve which opens and remains lopen so long as current'is supplied thereto-and which closes when the current is interrupted.l f I'his valve is provided with a manual operating lever-ll enclosed'in a housing Il and which is raised when the valve is closed and lowered when theV valve is opened. The housing Il isprovidedcin itstop with a hole Il adapted .toreceive the key member Il and has a latch Il pivoted thereon to engage the groove 42 At its upper end the ttingll is` in the key member to hold it down when desired. As shown in Figs. '1 and 8 when it is desired to open the valve I8 manually, the key member 40 may be inserted through the opening 80 to press the lever 58 down and the latch 82 may be engaged with the key member to hold it down thereby'holding the valve open.

A flow switch is preferably provided to insure that the blower 28 will continue in operation as long as gas is supplied to the furnace. As shown in Figs. 10 and 11, the ilow switch includes a casing 84 containing a ilexible diaphragm 88 and having pipe connections 88 to points in the supply pipe I4 on the opposite sides of the reducing valve I8.A When there is no flow of gas to the furnace, the diaphragm 88 will fall to the position shown in Fig. 10 but when gas is ilarly bridged by a switch bar I|8. The bars II4 and IIB are carried by an amature II8 operating in the coil 88.

In Fig. 12, the parts are shown in the off position in which both thermostat blades 18 and 80 are out of engagement with their respective contacts. At this time, the velocity vane 48 is moved to the position of Fig. 3 so that switch 52 is opened and since no fuel is flowing to the furnace, switch 12 is also open, though the fuel valve is closed and the blower is out of operation.

As the temperature in the space to be heated falls, the blades 18 and 80 will engage the contacts 82 and 84 respectively closing a circuit through the solenoid 88 and switch |08. This energizes the solenoid and raises the switch bars flowing, the differential pressure across the reducing valve will raise the diaphragm to the position shown in Fig. 11. In order to prevent deflection of the diaphragm when no gas is flowing, the reducing valve is. preferably provided with a restricted by-pass through which pressure on the opposite sides thereof will be equalized.

The casing 84 has mounted thereon a second casing 10 containing a pivoted mercury switch 12 which is operated by the diaphragm 88 through a rod 14. When the diaphragm is in its lowered position, the switch would be open and when the diaphragm is raised due to flow of gas, the switch will be closed.

Operation of the system is preferably con- Atrolled through a room thermostat 18 which may be mounted in the space to be heated. v

One desirable control circuit for the system as so far described is illustrated diagrammatically -in Figs. 12 and 13. As shown therein, the thermostat 18 includes a pair of blades 18 and 80 adapted to engage contacts 82 and 84 at different temperatures. For example, the blade 80 may be arranged to engage the contact 84 at 70 and the blade 18 may be arranged to engage the contact 82 at 72. The contact 82 is connected to a switch contact 88 and the contact 84 is connected through a solenoid 88 to one line 80 leading to a transformer or the like 82. A switch contact 84 complementary to the contact 88 is connected through a line 88 to the thermostat blades and also to a winding 98 on the supply valve I8. This valve as shown is a motor type valve. The winding 88 is connected through a safety pilot switch |00 which is closed when the pilot light is burning and opens when the pilot is extinguished to one side of the switch 52. This switch is connected in series with the switch 54 and through a line |02 to the power line 90.

The other power line |04 from the transformer 82 is connected to a switch contact |08 and through a limit control switch |08 to the contact 88. The limit control switch may be operated in response to a function of the furnace temperature so as to open when the furnace temperature reaches a predetermined degree. For example, with a hot water furnace, this switch may be opened when the water reaches a certain temperature and with a hot air furnace, it may be opened when the furnace structure itself attains a predetermined temperature. The line |04 is `I I4 and II8 to the position of Fig. 13 to complete circuits across the contacts 88 and 84 and the contacts |08 and ||0. At this time, the circuit is completed through the winding |I2 to start the blower 28 from line |04 through contact |08, switch bar ||8 and contact ||0 to the line 80. As the blower` starts, the vane 48 will be elevated and switch 52 will be closed to complete a circuit through the valve winding 88 from line 90 through line |02, switches 52 and 54, pilot switches |00, winding 88, contact 84, bar |I4, contact 86 and switch |08 to the line |04. Thus the valve I8 will be opened and gas will ilow to the furnace, being ignited by the pilot.

As soon as the gas starts to flow, the switch 12 will be closed due to the elevation of the diaphragm 88 to complete a holding circuit through the winding II2 of blower 28 in shunt across the contacts |08 and IIO. Since switch -12 will remain closed as long as fuel is flowing to the furnace, it will be apparent that the blower 28 will necessarily continue in operation as long as fuel is supplied to the furnace regardless of what occurs in the remainder of the control circuit. Thus, if for any reason, the valve I8 should stick open, the flue gases will continue to be evacuated by the blower.

As the temperature in the space rises above 70, the blade will move out of engagement with the contact 84. The winding 98 of the motor valve will, however, continue to be energized through a circuit from line |04, switch |08, contact 82, blade 18, line 86, winding 88, switch |00, switches 52 and 54 and line |02 back to the line 80. As the temperature continues to rise and reaches 72, the blade 18 will move out of engagement with the contact 82 to interrupt this holding circuit and the winding 88 will be deenergized. At this time the fuel valve I8 will close and when the flow of fuel is interrupted, the switch 12 will open to break the circuit .through the winding I|2 of the blower 28. 'I'he parts are now again in the position of Fig. 12

ready for the beginning of another heating cycle.

Fig. 14- illustrates a slightly modified circuit, parts therein corresponding to like parts in Figs. l2 and 13 being indicated by the same reference numerals. The principal distinction between this construction and that of Figs. 12 and 13 lies in the substitution of a. solenoid valve for the motor valve of the preceding figures. As shown, a solenoid coil* |20 is arranged in circuit in substantially the same manner as the winding 88 of Figs. l2 and 13 and when energized, raises a plunger |22 which opens the fuel supply to the furnace. Operation of this control system is substantially identicalto that described above and will not be repeated in detail.

In the event of a power failure or the like, it may be desired to operate the furnace manually and for this purpose the operator must remove the keymember 40 from the casing 38 in the manner described above. Removal of this member necessarily opens the switch 54 and at the same time opens the valve 32 to the stack connection. Thus the furnace cannot be operated manually unless the valve 32 is open and it cannot turn on automatically when the key member 40 is removed due to the fact that switch 54 is open. Y

Having removed the key member, the operator may insert lt through opening 60 in the valve casing 58 and may press down to depress the lever 55, thereby opening the fuel supply valve. By swinging the latch 62 into engagement with the grooved portion 42 of the key member, the' What is claimed is:

1. In a heating system having a furnace vided with fuel supply means and a stack connection, a heat extractor connected to the stack connection, a valve in the stack connection posterior to the connection to the heat extractor, means for controlling the supply of fuel to the furnace, a control circuit for said means including a switch controlled by operation of the heat and means for manually openingthe fuel supply means and for controlling said valve so that the fuel supply means cannot be opened ma'nually by said last named means except when th valve is open. l

2. In a heating system having a furnace provided with fuel supply means anda stack connection, a heat extractor connected to the stack connection, a valve in the stack connection posterior to the connection to the heat extractor, means for controlling the supply of fuel to the furnace, a control circuit for said means including a switch controlled by operation of the heat extractor and a switch controlled by said valve, a common detachable operating member for manually opening the fuel supply means and for controlling the valve, and means for preventing detachment of said member from the valve except when the valve is open.

3. In a heating system having a furnace provided with fuel supply means and a stack connection, a heat extractor connected to the stack connection, a valve in the stack connection posterior to the connection to the heat extractor, means rfor controlling the supply of fuel to the furnace, a control circuit for said means including a switch controlled by operation of the heat extractor and a switch controlled by said valve, to be closed when the valve is closed and open v when the valve is open, a common detachable operating member for manually opening the fuel supply means and for controlling the valve, and means for preventing detachment of said member from the valve except when the valve is open, whereby the fuel supply means can be opened manually only when the valve and the switch controlled thereby are both open.

4. In a heating system having a furnace provided 1with fuel supply means and a stack connection, a heat extractor connected to the stack connection, a valve in the stack connection posterior to the connection to the heat extractor,

' 4 extractor and a switch controlled by said valve,

ing a switch controlled by ow of gas through the heat extractor and a second switch controlled by the valve to be open when the valve is open and closed when the valve is closed, a common key member for manually controlling the fuel supply means and for opening and closing the valve, and means to prevent removal of said key member ":from the valve except when the valve is open.

5. In a heating system having a furnace, supply means for uid fuel including a supply valve, and a flue connection, the combination of a valve in the flue' connection controlling communication thereof with a stack or the like, a common detachable operating member for both of said valves, and means for preventing removal of said member from the last named valve except when it is open so that the supply valve cannot be opened by said member unless the valve in the flue connection is open.

6. In a heating system having a furnace, supply means for fluid fuel-including a supply valve. and a ue connection, the combination of electrical means for controlling the supply valve, a control circuit for said electrical means, electrical means for withdrawing flue gas through said ue connection, a control circuit for said last named electrical' means, thermostatic means responsive to the' temperature of the space heated by said system for controlling both of said control circuits, and pressure responsive means connected to the fuel supply means and responsive to the flow of fuel to the furnace to hold the second named control circuit closed as long as fuel is flowing.

7. In a heating system having a furnace, supply means for fluid fuel including a supply valve, and a flue connection, the combination of electrical means for controlling the supply valve, a control circuit for said electrical means, electrical means for withdrawing flue gas through said flue connection, a control circuit for said last named electrical means, a thermostatically operated switch in the second named control circuit controlling said second named electrical means in response to the temperature of the space heated by said system, a second switch in the second control circuit in shunt with the thermostatically operated switch, means responsive to the flow of fuel to the furnace to close said second switch, and a switch in the first named control circuit closed in response to the flow of gas through the flue connection.

r JAMES G. AMES.

,NOltltlANA C. PENFOID. 

